Fellow fork: css-modules webpack-parity hashing + GH Packages publishing#2
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Fellow fork: css-modules webpack-parity hashing + GH Packages publishing#2
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These will back new HashAlgorithm options in the next commit, enabling webpack/css-loader-compatible scoped-name hashes.
…tions helper Introduces a parameterized hash-and-encode helper for CSS module names, with md4 and xxhash64 algorithms and standard-base64 / hex digests. The default [hash] / [content-hash] code path is unchanged; this commit only adds the new types and helper. Pattern parsing and Segment wiring follow in subsequent commits. Tested against ground-truth output captured from a Vite/postcss-modules build to confirm md4+base64+truncate behaves identically to webpack's loader-utils.getHashDigest.
…nd length Segment::Hash becomes a struct variant carrying optional HashAlgorithm, DigestType, and length fields. When all are None the legacy siphash + custom-base64 path is preserved (existing test snapshots unchanged); when any is Some, hashing dispatches through hash_with_options. Hash computation moves from CssModule::new to Pattern::write so each segment can apply its own options. CssModule::hashes is renamed to hash_inputs and now stores the raw source-relative path string instead of a precomputed hash. Pattern::write computes the hash per segment from this raw input. Segment::ContentHash remains a unit variant in this commit; per-segment options on [content-hash] would require additional plumbing through the bundler's content-hash precomputation and is left for a follow-up.
…] syntax The parser now recognizes webpack-compatible scoped-name hash placeholders. Each of algo, digest, and length is optional; the position of the literal \`hash\` keyword distinguishes algo (before) from digest+length (after). Examples: [hash] -> legacy lightningcss hash, unchanged [hash:base64] -> default algo, base64 digest, full length [hash:5] -> default algo, hex digest, 5 chars [md4:hash:base64:5] -> md4 + base64 + 5 chars (matches webpack) [xxhash64:hash:hex:12] -> xxhash64 + hex + 12 chars Bare \`[hash]\` keeps the legacy code path so existing snapshots remain byte- identical. Recognized algorithms: md4, xxhash64. Recognized digests: hex, base64. Parsing is case-insensitive. Unknown algos/digests, missing \`hash\` keyword, and extra parts before \`hash\` all return UnknownPlaceholder. Tests cover each form, case-insensitivity, rejection of bad input, and a round-trip integration test against ground-truth output captured from a Vite/postcss-modules build (digest only; the css-loader content composition and post-processing pipeline live downstream of this commit).
Adds a hash_prefix field to css_modules::Config that prepends a string to every hash input. This matches Vite/postcss-modules' hashPrefix option and, when set to '\x00\x00\x00\x00', reproduces css-loader's tier-0 salt input byte-for-byte — a necessary piece for Vite-to-webpack scoped-name parity. Default is None, leaving lightningcss output unchanged for existing users. Per-local hash composition and post-processing (also required for full Vite parity) follow in subsequent commits.
Adds a hash_local_name flag to css_modules::Config. When true, the local class/ident name is appended to the hash input separated by a NUL byte: <prefix><relative-path>\0<local>. This matches the per-local hashing done by css-loader and postcss-modules — without it every export from a given file shares one hash. Composition happens via a new CssModule::hash_input_for helper, called from each Pattern::write call site (add_local, add_dashed, reference, reference_dashed, handle_composes, plus printer's write_ident and write_dashed_ident). Each call allocates a small string when hash_local_name is enabled; otherwise it returns Cow::Borrowed against the existing buffer. Default is false, preserving lightningcss's per-file hashing for users who don't opt in. Combined with hash_prefix from the previous commit, the bytes fed to the hash now match css-loader's input bytes exactly. A test asserts that Md4+Base64+5 over the composed input reproduces the captured Vite digest 'YTbdH' for src/styles/Alpha.module.css#foo.
Adds an escape_scoped_names config flag and an escape_scoped_name helper that mirrors css-loader/postcss-modules' genericNames post-processing: s.replace(/[^a-zA-Z0-9\\-_\\u00A0-\\uFFFF]/g, '-') .replace(/^((-?[0-9])|--)/, '_\$1') The pipeline runs after Pattern::write_to_string at every scoped-name call site (CssModule::add_local/add_dashed/reference/reference_dashed/handle_composes plus Printer::write_ident/write_dashed_ident). For dashed (custom property) idents the leading '--' is excluded — the rendered pattern is escaped without the prefix and '--' is prepended afterwards, so '--' on a custom property never triggers the leading-double-dash rule. write_to_string is also promoted from private to pub(crate) so the printer can call it directly (replacing the previous streaming Pattern::write + serialize_identifier/serialize_name closure pattern). Output is unchanged for the legacy (no-escape) path: serialize_identifier on a full string produces the same bytes as serialize_identifier on the head + serialize_name on the tail. Eight unit tests cover the four post-process branches captured from the real Vite/postcss-modules build (digit, +, /, leading -digit, leading --, leading -letter unchanged, clean input, unicode above U+00A0).
Integrates the four hashing features (md4/xxhash64 algos, hash_prefix, hash_local_name, escape_scoped_names) and asserts the rendered scoped names match a Vite/postcss-modules build's output byte-for-byte, using the generateScopedName='[name]__[local]__[md4:hash:base64:5]' and hashPrefix='\\0\\0\\0\\0' configuration captured from a real project. Twelve cases across two source files cover every post-processing branch: clean digest, +/-/-cleanup-mid-name, leading-digit prefix on rendered output, leading -digit prefix, leading -- prefix, and leading -letter (no prefix). If this test breaks, lightningcss has diverged from webpack/css-loader hashing and Vite migrations relying on hash stability will produce different class names than they did pre-migration.
GitHub Packages requires scoped names matching the publishing org. Rename the top-level package and the eleven platform-specific binary packages from 'lightningcss[-platform]' to '@fellowapp/lightningcss[-platform]', update node/index.js to require the scoped platform package at runtime, and point publishConfig.registry at https://npm.pkg.github.com. Drop CLI packaging from build-npm.js — the fork is consumed as a library (via Vite/lightningcss-napi), not as a CLI, and the per-platform CLI bundles are dead weight. Version bumped to 1.32.0-fellow.0 so the fork doesn't shadow upstream.
Adapted from .github/workflows/release.yml. Builds the same matrix of
platform-specific .node binaries (10 targets: macOS x64/arm64, Windows
x64/arm64, Linux x64/arm64 gnu+musl, Linux armv7, Android arm64) and
publishes them to GitHub Packages as @fellowapp/lightningcss-<platform>,
plus the main @fellowapp/lightningcss package.
Differences from the upstream workflow:
- Triggered on workflow_dispatch only (no automated tag-based release).
- Drops FreeBSD and wasm targets (not needed for the Vite-via-napi use case).
- Drops CLI build/publish (the fork is consumed as a library).
- Authenticates with GITHUB_TOKEN against npm.pkg.github.com via
setup-node's registry-url + scope inputs.
- Requires permissions: { packages: write, contents: read } on the
release job.
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Summary
Forks
lightningcssto add four CSS-modules scoped-name hashing features needed for byte-parity with webpack/css-loader/postcss-modules, and packages the result for distribution via GitHub Packages as@fellowapp/lightningcss.The first 4 commits are upstreamable as-is and will be sent to
parcel-bundler/lightningcssseparately (see branchfeat/css-modules-hash-algorithms). The remaining commits are Fellow-specific.CSS modules changes (commits 1-8)
feat(css-modules): add HashAlgorithm and DigestType+hash_with_optionshelper (md4, xxhash64; hex, standard base64)feat(css-modules): extend Segment::Hash with optional algo, digest, length(struct variant)feat(css-modules): parse webpack-style [<algo>:hash:<digest>:<length>] syntaxfeat(css-modules): add Config::hash_prefix(Vite/postcss-modules'hashPrefix; matches css-loader tier-0 salt)feat(css-modules): add Config::hash_local_name(per-(file, local) hashing)feat(css-modules): add Config::escape_scoped_names(post-process pipeline making +/ safe and prefixing leading-digit/-- with _)test(css-modules): add Vite scoped-name byte-parity end-to-end test(12 captured cases reproduce byte-for-byte)All defaults preserve existing lightningcss output: each Fellow-specific feature is an opt-in flag.
Packaging changes (commits 9-10)
chore(npm): rename package to @fellowapp/lightningcss for GH Packages— scoped names + GH Packages registry + dropped CLI publishingci: add release-fellowapp workflow to publish to GitHub Packages—workflow_dispatch-triggered build matrix (10 platform targets) authenticating withGITHUB_TOKENTest plan
cargo test --no-default-features— 135 pass (only pre-existing platform-dependenttest_dependenciesfailure remains, unrelated to this work)@fellowapp/lightningcss@1.32.0-fellow.0resolves from GH Packagespnpm.overrides